The present invention relates generally to a device for heating solids. The solids being heated are heat exchange bodies such as metallic or ceramic balls or pebbles, which are preferably used in rotating retorts for heating and crushing materials which are being processed.
Such solid heat exchange bodies, referred to hereinafter as solids, are used in the pyrolytic processing of oil shale or other solid carbonaceous materials. The solids are utilized to heat the carbonaceous material (e.g. oil shale) by exchanging their heat to the material being processed by means of intimate contact therewith. When the carbonaceous materials are heated to the desired temperature, the solids are returned to a device which reheats the solid heat carrying bodies. Typical of such devices for heating solids is the device disclosed in U.S. Pat. No. 3,595,540.
A main characteristic of these devices for heating and/or reheating solids utilizes a flow of solid bodies into a heating chamber. A concurrent flow of hot flue gas is provided to heat the individual solids within the heating chamber. Once the heating function has taken place, it is necessary to separate the concurrent flow of hot flue gas and the now heated solids. Prior art devices have utilized continuous-circumferential channel-like disengagers superimposed over a series of hot flue gas outlets. Due to the high temperatures involved and the systematic nonuniformity of heating of the solids within the heating chamber, there was a tendency for some sections of the channel-like solid disengager to overheat. Sectional overheating created excessive thermal stresses and resulted in warping of the disengager thereby restricting solids flow in parts of the heating device. Also, corrosion of the overheated sections of the disengager was accelerated, thereby reducing the operating life time of the disengager mechanism and necessitating the use of expensive alloys which resist corrosion at elevated temperatures.